Dataset Information

HIV-1 subtype C Envelope function becomes less sensitive to N-glycosylation deletion during disease progression.

ABSTRACT: OBJECTIVE:As part of a larger study to understand how Envelope N-glycosylation influences HIV-1 pathogenesis, we selected a participant infected with a single Subtype C variant and determined whether deletion of specific potential N-glycan sites (PNGs) impacted Envelope function longitudinally. RESULTS:We deleted five PNGs previously linked to HIV-1 transmission of two matched Envelope clones representing variants at 5 and 173 weeks post-infection. The transmitted founder (TF) had significantly better pseudovirus entry efficiency than the chronic infection (CI) variant. Deletion of all PNGs significantly reduced TF entry efficiency, binding to dendritic cell-specific intracellular adhesion molecule 3 grabbing non-integrin (DC-SIGN) receptor and trans-infection. However, mutational analysis did not affect the phenotype of the CI Envelope to the same extent. Notably, deletion of the PNGs at N241 and N448 had no effect on CI Envelope function, suggesting that some PNGs might only be important during acute infection. Therefore, vaccines that elicit antibodies against N-glycans important for TF Envelope function could drive the loss of PNGs during immune escape, abrogating viral replication. Conversely, changes in N-glycosylation might have no effect on some variants, reducing vaccine efficacy. This finding highlights the need for further investigation into the role of Envelope N-glycosylation in HIV-1 pathogenesis.

SUBMITTER: Lumngwena EN

PROVIDER: S-EPMC6580609 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

HIV-1 subtype C Envelope function becomes less sensitive to N-glycosylation deletion during disease progression.

Lumngwena Evelyn Ngwa EN Shuping Liliwe L Bernitz Netanya N Woodman Zenda Z

BMC research notes 20190617 1

<h4>Objective</h4>As part of a larger study to understand how Envelope N-glycosylation influences HIV-1 pathogenesis, we selected a participant infected with a single Subtype C variant and determined whether deletion of specific potential N-glycan sites (PNGs) impacted Envelope function longitudinally.<h4>Results</h4>We deleted five PNGs previously linked to HIV-1 transmission of two matched Envelope clones representing variants at 5 and 173 weeks post-infection. The transmitted founder (TF) had ...[more]

PMID: 31208438

Similar Datasets

Project description:HIV-1 envelope diversity remains a significant challenge for the development of an efficacious vaccine. The evolutionary forces that shape the diversity of envelope are incompletely understood. HIV-1 subtype C envelope in particular shows significant differences and unique characteristics compared to its subtype B counterpart. Here we applied the single genome sequencing strategy of plasma derived virus from a cohort of therapy naïve chronically infected individuals in order to study diversity, divergence patterns and envelope characteristics across the entire HIV-1 subtype C gp160 in 4 slow progressors and 4 progressors over an average of 19.5 months.Sequence analysis indicated that intra-patient nucleotide diversity within the entire envelope was higher in slow progressors, but did not reach statistical significance (p = 0.07). However, intra-patient nucleotide diversity was significantly higher in slow progressors compared to progressors in the C2 (p = 0.0006), V3 (p = 0.01) and C3 (p = 0.005) regions. Increased amino acid length and fewer potential N-linked glycosylation sites (PNGs) were observed in the V1-V4 in slow progressors compared to progressors (p = 0.009 and p = 0.02 respectively). Similarly, gp41 in the progressors was significantly longer and had fewer PNGs compared to slow progressors (p = 0.02 and p = 0.02 respectively). Positive selection hotspots mapped mainly to V1, C3, V4, C4 and gp41 in slow progressors, whereas hotspots mapped mainly to gp41 in progressors. Signature consensus sequence differences between the groups occurred mainly in gp41.These data suggest that separate regions of envelope are under differential selective forces, and that envelope evolution differs based on disease course. Differences between slow progressors and progressors may reflect differences in immunological pressure and immune evasion mechanisms. These data also indicate that the pattern of envelope evolution is an important correlate of disease progression in chronic HIV-1 subtype C infection.

Project description:UnlabelledThe gp120/gp41 HIV-1 envelope glycoprotein (Env) is highly glycosylated, with up to 50% of its mass consisting of N-linked glycans. This dense carbohydrate coat has emerged as a promising vaccine target, with its glycans acting as epitopes for a number of potent and broadly neutralizing antibodies (bnAbs). Characterizing the glycan structures present on native HIV-1 Env is thus a critical goal for the design of Env immunogens. In this study, we used a complementary, multistep approach involving ion mobility mass spectrometry and high-performance liquid chromatography to comprehensively characterize the glycan structures present on HIV-1 gp120 produced in peripheral blood mononuclear cells (PBMCs). The capacity of different expression systems, including pseudoviral particles and recombinant cell surface trimers, to reproduce native-like glycosylation was then assessed. A population of oligomannose glycans on gp120 was reproduced across all expression systems, supporting this as an intrinsic property of Env that can be targeted for vaccine design. In contrast, Env produced in HEK 293T cells failed to accurately reproduce the highly processed complex-type glycan structures observed on PBMC-derived gp120, and in particular the precise linkage of sialic acid residues that cap these glycans. Finally, we show that unlike for gp120, the glycans decorating gp41 are mostly complex-type sugars, consistent with the glycan specificity of bnAbs that target this region. These findings provide insights into the glycosylation of native and recombinant HIV-1 Env and can be used to inform strategies for immunogen design and preparation.ImportanceDevelopment of an HIV vaccine is desperately needed to control new infections, and elicitation of HIV bnAbs will likely be an important component of an effective vaccine. Increasingly, HIV bnAbs are being identified that bind to the N-linked glycans coating the HIV envelope glycoproteins gp120 and gp41, highlighting them as important targets for vaccine design. It is therefore important to characterize the glycan structures present on native, virion-associated gp120 and gp41 for development of vaccines that accurately mimic native-Env glycosylation. In this study, we used a number of analytical techniques to precisely study the structures of both the oligomannose and complex-type glycans present on native Env to provide a reference for determining the ability of potential HIV immunogens to accurately replicate the glycosylation pattern on these native structures.

Project description:The addition of asparagine (N)-linked polysaccharide chains (i.e., glycans) to the gp120 and gp41 glycoproteins of human immunodeficiency virus type 1 (HIV-1) envelope is not only required for correct protein folding, but also may provide protection against neutralizing antibodies as a "glycan shield." As a result, strong host-specific selection is frequently associated with codon positions where nonsynonymous substitutions can create or disrupt potential N-linked glycosylation sites (PNGSs). Moreover, empirical data suggest that the individual contribution of PNGSs to the neutralization sensitivity or infectivity of HIV-1 may be critically dependent on the presence or absence of other PNGSs in the envelope sequence. Here we evaluate how glycan-glycan interactions have shaped the evolution of HIV-1 envelope sequences by analyzing the distribution of PNGSs in a large-sequence alignment. Using a "covarion"-type phylogenetic model, we find that the rates at which individual PNGSs are gained or lost vary significantly over time, suggesting that the selective advantage of having a PNGS may depend on the presence or absence of other PNGSs in the sequence. Consequently, we identify specific interactions between PNGSs in the alignment using a new paired-character phylogenetic model of evolution, and a Bayesian graphical model. Despite the fundamental differences between these two methods, several interactions are jointly identified by both. Mapping these interactions onto a structural model of HIV-1 gp120 reveals that negative (exclusive) interactions occur significantly more often between colocalized glycans, while positive (inclusive) interactions are restricted to more distant glycans. Our results imply that the adaptive repertoire of alternative configurations in the HIV-1 glycan shield is limited by functional interactions between the N-linked glycans. This represents a potential vulnerability of rapidly evolving HIV-1 populations that may provide useful glycan-based targets for neutralizing antibodies.

Dataset Information

HIV-1 subtype C Envelope function becomes less sensitive to N-glycosylation deletion during disease progression.

Publications

HIV-1 subtype C Envelope function becomes less sensitive to N-glycosylation deletion during disease progression.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets